In an increasing number of coronary and structural heart disease interventional procedures, percutaneous devices, for example stents, are placed and deployed in coronary arteries. These devices, which are collapsed onto a catheter for delivery, must be precisely sized and positioned for deployment during the procedure and often require evaluation afterwards. Once these devices are deployed into their final complex three-dimensional structure, the evaluation process is often subjective and non-standardized, such that tracking any clinical outcomes related to the position, sizing, or final shape of the structure can be difficult.
Evaluation of percutaneous devices directly after deployment or over longer time periods is currently accomplished only via visual inspection of 2D images acquired by X-ray examination apparatuses or by other imaging modalities, e.g. echocardiography. However, many of these devices have complex 3D shapes that are both difficult to assess using conventional projection-based imaging and which may change their shape in a way that is hard to discern with the eye alone. As more of these devices are being developed and require clinical evaluation for short- and long-term safety and efficacy, more advanced methods for determining their proper deployment and positioning over time may be required.
In WO 2008/041154 A2 a spatial characterization of a structure located within an object by identifying 2D representations of the structure within section planes is shown. There, a virtual pullback as a visualization and quantification tool that allows an interventional cardiologist to easily assess stent expansion is described. The virtual pullback visualizes the stent and/or the vessel lumen similar to an intravascular ultrasound pullback. The virtual pullback is performed in volumetric data along a reference line. The volumetric data can be a reconstruction of rotational 2D X-ray attenuation data. Planes perpendicular to the reference line are visualized as the position along the reference line changes. In these perpendicular section planes automatic measurement are calculated and displayed.